Near-eye display systems, such as head-mounted displays, present virtual content to the eyes of a user. To provide a realistic virtual image or hologram, the virtual content may be stereoscopically rendered from the point of view of each eye. To determine each eye's point of view, an estimated location of each of the user's eyes may be determined. In one example, the interpupillary distance (IPD) of the user and/or one or more assumptions regarding a location of the eyes relative to the display may be assumed or ascertained.
However, the use of an IPD to determine an estimated location of a user's eyes may pose various challenges. For example, depending upon the age, gender and other characteristics of a user, an IPD may range from 40 mm or less to 73 mm or more. Thus, using an assumed IPD introduces uncertainty into the accuracy of the corresponding estimated location. Further, directly measuring the IPD of a user typically involves an optical professional measuring the user's IPD using a millimeter ruler or a corneal reflex pupillometer. Visiting such a professional to acquire an IPD measurement may impose a significant inconvenience on a user of a near-eye display, as well as additional expense.
Additionally, it will be appreciated that an IPD value provides the distance between the pupils of each eye, without reference to each eye's location relative to the actual near-eye display. Thus, using solely an IPD value to estimate a user's eye location provides limited information with regard to each eye's actual location relative to the display.